KR102491408B1 - Method for manufacturing a polarizing plate, method for manufacturing an optical film, and polymerizable liquid crystal composition - Google Patents

Abstract

An object of the present invention is to provide a method for producing a polarizing plate excellent in optical stability, a method for producing an optical film, and a polymerizable liquid crystal composition when the adhesion between a polarizer and an optically anisotropic layer is improved and applied to an image display device. The method for producing a polarizing plate of the present invention is a layer forming step of forming a liquid crystal composition layer composed of a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond and a photopolymerization initiator, on a substrate And, a semi-curing step of curing the liquid crystalline composition layer to form a semi-curing layer that satisfies a predetermined curing profile, bonding the polarizer and the semi-curing layer using an ultraviolet curing adhesive, and a polarizer and an ultraviolet curing adhesive and a radius A bonding step of producing a laminate in which a cured layer and a base material are laminated in this order, and a main curing step of producing a polarizing plate having a polarizer and an optically anisotropic layer in which the laminate is cured and the semi-cured layer is further cured A polarizing plate having is a manufacturing method of

Description

Method for manufacturing a polarizing plate, method for manufacturing an optical film, and polymerizable liquid crystal composition

The present invention relates to a method for producing a polarizing plate, a method for producing an optical film, and a polymerizable liquid crystal composition.

A polarizing plate is used as a member of a liquid crystal display (LCD) and an organic light emitting diode (OLED) or the like, and plays an important role in the display performance thereof.

In addition, a general polarizing plate has a structure in which an optical film is bonded to one side or both sides of a polarizing film (polarizer) in which a dichroic dye such as an iodine complex is adsorbed and oriented to a polyvinyl alcohol (PVA)-based resin.

And, conventionally, as such an optical film, a film having a retardation layer (optically anisotropic layer) in which a liquid crystalline compound is coated on a transparent support through an alignment film and the alignment state is fixed has been widely studied. When bonding with a polarizer, the structure which bonds the transparent support body side of an optical film to a polarizer was common (for example, refer patent document 1 etc.).

Recently, from the viewpoints of further thinning of the polarizing plate, wide viewing angle, etc., a configuration in which the retardation layer (optically anisotropic layer) side of the optical film is bonded to the polarizer has been proposed, and the retardation layer (optically anisotropic layer) to the polarizer A method of peeling the transparent support after bonding has also been proposed (for example, see Patent Document 2 and the like).

Japanese Unexamined Patent Publication No. 2007-249108 Japanese Unexamined Patent Publication No. 2012-220554

The present inventors studied the polarizing element (polarizing plate) described in Patent Literature 2, and when the organosilicon compound layer formed on the polarizer-side surface of the liquid crystal layer (optically anisotropic layer) was omitted, depending on the adhesive used , It was found that the alignment state of the liquid crystal layer was changed when the adhesive penetrated into the liquid crystal layer, and as a result, when applied to an image display device, the display performance decreased and the optical stability was poor. Moreover, it turned out that the adhesiveness of a polarizer and a liquid crystal layer becomes inadequate depending on the adhesive agent used.

Therefore, an object of the present invention is to provide a method for producing a polarizing plate excellent in optical stability, a method for producing an optical film, and a polymerizable liquid crystal composition when the adhesion between a polarizer and an optically anisotropic layer is improved and applied to an image display device. do.

As a result of intensive examination to achieve the above object, the present inventors use a semi-cured layer that satisfies a predetermined curing profile for bonding with a polarizer, and re-curing after bonding to obtain an optically anisotropic layer, so that the polarizer and the optically anisotropic layer When adhesiveness became favorable and it applied to an image display apparatus, it discovered that the polarizing plate excellent in optical stability could be manufactured, and this invention was completed.

That is, it discovered that the said subject could be achieved by the following structure.

[1] a layer forming step of forming a liquid crystal composition layer comprising a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond and a photopolymerization initiator on a substrate;

A semi-curing step of curing the liquid crystalline composition layer to form a semi-curing layer that satisfies Formulas (1) and (2) described later;

A bonding step of bonding the polarizer and the semi-curing layer using an ultraviolet curable adhesive to produce a laminate in which the polarizer, the ultraviolet curing adhesive, the semi-curing layer, and the base material are laminated in this order;

The manufacturing method of the polarizing plate which has the main hardening process of hardening|curing a laminated body and producing the polarizing plate which has a polarizer and the optically anisotropic layer in which a semi-cured layer is further hardened.

[2] The manufacturing method of the polarizing plate as described in [1] which has a peeling process of peeling a base material from a laminated body after a main hardening process.

[3] As a method for producing an optical film having a substrate and a semi-cured layer,

A layer formation step of forming a liquid crystal composition layer comprising a liquid crystal composition layer comprising a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator on a substrate,

A method for producing an optical film comprising a semi-curing step of curing a liquid crystalline composition layer to form a semi-curing layer that satisfies Formulas (1) and (2) described later.

[4] As a method for producing an optical film having a substrate and a semi-cured layer,

A polymerizable liquid crystal containing, on a substrate, a copolymer having a liquid crystalline compound having a polymerizable group, a photopolymerization initiator, and a repeating unit A represented by formula (A) described later and a repeating unit B represented by formula (B) described later. A layer forming step of forming a liquid crystalline composition layer composed of the composition;

A method for producing an optical film comprising a semi-curing step of curing a liquid crystalline composition layer to form a semi-curing layer that satisfies Formulas (1) and (2) described later.

[5] described in [3] or [4], wherein the polymerizable liquid crystal composition exhibits a nematic phase and a smectic phase in this order on the low-temperature side of the isotropic phase, and the semi-cured layer is a layer in which the polymerizable liquid crystal composition is fixed in a smectic phase. A method for manufacturing an optical film.

[6] A polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator.

[7] A polymerizable liquid crystal composition containing a copolymer having a liquid crystalline compound having a polymerizable group, a photopolymerization initiator, and a repeating unit A represented by formula (A) described later and a repeating unit B represented by formula (B) described later .

ADVANTAGE OF THE INVENTION According to this invention, the adhesiveness of a polarizer and an optically anisotropic layer becomes favorable, and when applied to an image display apparatus, the manufacturing method of the polarizing plate excellent in optical stability, the manufacturing method of an optical film, and a polymeric liquid crystal composition can be provided.

Hereinafter, the present invention will be described in detail.

The description of the constitutional requirements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.

In addition, in this specification, the numerical range expressed using "-" means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

Incidentally, in this specification, parallel and orthogonal do not mean parallel and orthogonal in a strict sense, but mean a range of ±5° from parallel or orthogonal, respectively.

In the present specification, "(meth)acrylate" is a notation meaning either acrylate or methacrylate, and "(meth)acryl" is a notation meaning either acryl or methacryl. And "(meth)acryloyl" is a notation meaning either acryloyl or methacryloyl.

In addition, in this specification, the liquid crystal composition and the liquid crystal compound are also included as a concept that have already ceased to exhibit liquid crystallinity due to curing or the like.

《Retardation》

In the present invention, Re(λ) and Rth(λ) represent in-plane retardation and thickness direction retardation at wavelength λ, respectively. When there is no description in particular, the wavelength λ is 550 nm.

In the present invention, Re(λ) and Rth(λ) are values measured at a wavelength λ in AxoScan OPMF-1 (manufactured by Opto Science). By entering the average refractive index ((Nx+Ny+Nz)/3) and film thickness (d (μm)) in AxoScan,

Slow axis direction (°)

Re(λ)=R0(λ)

Rth(λ)=((Nx+Ny)/2-Nz)×d is calculated.

[Method for producing polarizing plate]

The method for producing a polarizing plate of the present invention is a layer forming step of forming a liquid crystal composition layer composed of a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond and a photopolymerization initiator, on a substrate class,

A semi-curing step of curing the liquid crystalline composition layer to form a semi-curing layer satisfying the following formulas (1) and (2);

A bonding step of bonding the polarizer and the semi-curing layer using an ultraviolet curable adhesive to produce a laminate in which the polarizer, the ultraviolet curing adhesive, the semi-curing layer, and the base material are laminated in this order;

It has a main curing step of producing a polarizing plate having a polarizer and an optically anisotropic layer formed by curing the laminate and further curing the semi-cured layer.

1.5≤Sa/Sb≤5.0 Equation (1)

0.03≤(P1-P2)/P3≤0.2 Equation (2)

In the above formula (1), Sa is from the surface of the semi-cured layer on the opposite side to the base material of the semi-cured layer after Br staining of the ethylenically unsaturated double bonds contained in the semi-cured layer to a distance of 1/4 of the film thickness of the semi-cured layer Indicates the integral value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in the region.

In the above formula (1), Sb is from the surface of the semi-cured layer on the substrate side after Br staining of the ethylenically unsaturated double bonds contained in the semi-cured layer to the region of the distance of 3/4 of the film thickness of the semi-cured layer represents the integral value of secondary ion intensity derived from Br ions detected by time-of-flight secondary ion mass spectrometry.

In the above formula (2), P1 represents the absorbance at the maximum absorption peak in the range of wave numbers 820 to 800 cm ^-1 in the infrared absorption spectrum, and P2 represents the absorbance at the minimum wave number in the range of 840 to 800 cm ^-1 . It represents the absorbance, and P3 represents the absorbance at the maximum absorption peak in the range of 1800 to 1650 cm ⁻¹ wave number.

The hardening profile shown in said formula (1) and (2) is demonstrated in detail.

First, said Formula (1) is an index which shows that the residual amount of ethylenically unsaturated double bonds is distributed in the thickness direction. In addition, although it is a range not included in the said Formula (1), when Sa/Sb is 1.0, it shows that hardening is advancing uniformly in the thickness direction.

Next, the formula (2) is an index indicating the amount of ethylenically unsaturated double bonds remaining in the entire layer, and is a rule indicating that the entire layer is cured to some extent. Specifically, P1 in the above formula (2) represents the absorbance at the maximum absorption peak derived from the remaining ethylenically unsaturated double bond, P2 represents the minimum absorbance as a baseline, and P3 represents P1 and P2. The absorbance at the absorption maximum peak derived from the acetyl group for normalizing the difference in absorbance of

Here, Sa and Sb in the above formula (1), as described above, can be measured by time-of-flight secondary ion mass spectrometry (TOF-SIMS), but specifically As such, it can be measured by TOF-SIMS under the measurement conditions shown below.

<TOF-SIMS measurement conditions>

Measurement by TOF-SIMS in the present invention is measured as shown below.

(1) The layer obtained by semi-curing the liquid crystalline composition layer, which is to be measured, was obliquely cut in the thickness direction with an ultra microtome to expose a cross section. After that, the obliquely cut sample is Br dyed. In addition, Br staining is carried out by vapor phase modification of the sample with 0.3% bromine water in order to add Br to the double bond.

(2) After Br staining, the exposed cross section is measured under the following equipment and conditions.

Device: TOF-SIMS 4 (manufactured by ION-TOF)

Primary ion: Bi ³⁺ primary ion gun (25kV, 0.2pA)

・Electrification correction: Combined use of 20 eV slow electron gun

・Measurement area: 300mm×300mm

・Raster: 256×256pixels

・Number of integrations: 16 times

In the present invention, as described above, a semi-cured layer satisfying the curing profile shown in the above formulas (1) and (2) is used for bonding with a polarizer, and re-cured after bonding to form an optically anisotropic layer, thereby forming a polarizer and The adhesiveness of the optically anisotropic layer becomes good, and a polarizing plate having excellent optical stability when applied to an image display device can be manufactured.

Although this is not clear in detail, the present inventors estimate as follows.

That is, when the present inventors use a semi-cured layer that satisfies the curing profile shown in the above formulas (1) and (2), the ultraviolet curable adhesive used for bonding with the polarizer is radial from the surface of the substrate on the opposite side of the semi-cured layer. Appropriately penetrates into the region up to a distance of 1/4 of the film thickness of the cured layer, and becomes difficult to penetrate into the region from the surface of the semi-cured layer on the substrate side to the distance of 3/4 of the film thickness of the semi-cured layer. It is estimated that the adhesiveness of and the optical stability at the time of application to an image display device can be made compatible.

Hereinafter, each process of the manufacturing method of the polarizing plate of the present invention and the member used in each process will be described in detail.

[Layer Formation Step]

The layer formation step of the method for producing a polarizing plate of the present invention includes, on a substrate, a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond and a photopolymerization initiator (hereinafter referred to as "specific polymerizable It is a process of forming a liquid crystal composition layer composed of a liquid crystal composition (also abbreviated as “liquid crystal composition”).

<Description>

The substrate is not particularly limited as long as it is a substrate for supporting a liquid crystal composition layer composed of a specific polymerizable liquid crystal composition.

Such a substrate preferably has a film thickness of 5 to 100 μm, more preferably 10 to 75 μm, and still more preferably 15 to 55 μm.

When the film thickness is 5 µm or more, it is easy to ensure sufficient mechanical strength and it is difficult to cause failures such as curling, wrinkles, and buckling, so it is preferable.

In addition, when the film thickness is 100 μm or less, when the multilayer film of the base material and the semi-cured layer described later is stored, for example, in the form of a long roll, it is easy to adjust the surface pressure applied to the multilayer film to an appropriate range, resulting in failure of adhesion Since this is difficult to occur, it is preferable.

The surface energy of the substrate is not particularly limited, but by adjusting the relationship between the surface energy of a specific polymerizable liquid crystal composition and the surface energy of the substrate on which the liquid crystal composition layer is provided, the relationship between the liquid crystal composition layer and the substrate Adhesion can be adjusted.

When the difference in surface energy is reduced, the adhesive force tends to increase, and when the difference in surface energy is increased, the adhesive force tends to decrease.

In addition, the surface irregularities of the substrate are not particularly limited, but the relationship between the surface energy, hardness, and surface irregularities of the semi-cured layer described later and the surface energy and hardness of the surface of the substrate opposite to the side on which the liquid crystalline composition layer is provided is Depending on the relationship, it can be adjusted for the purpose of preventing adhesion failure when, for example, a substrate and a multilayer film of a semi-cured layer described later are stored in the form of a long roll.

If the surface irregularities are increased, adhesion failure tends to be suppressed, and if the surface irregularities are reduced, the surface irregularities of the functional film tend to decrease and the haze of the functional film tends to decrease, and can be appropriately set. In addition, a protective film may be provided on the side of the substrate opposite to the side on which the liquid crystalline composition layer is provided, in order to prevent adhesive failure in a roll form or to impart transportability to the substrate.

As such a base material, well-known materials and films can be used suitably.

Specific examples of the material include polyester polymers, olefin polymers, cycloolefin polymers, (meth)acrylic polymers, cellulose polymers, polyamide polymers, and the like.

In particular, polyester-based polymers and olefin-based polymers are preferable as the material for the base film, polyester-based polymers are more preferable, and polyethylene terephthalate (PET) is particularly preferable among polyester-based polymers.

In addition, for the purpose of adjusting the surface properties of the substrate, appropriate surface treatment can be performed. In order to lower the surface energy, for example, corona treatment, normal temperature plasma treatment, saponification treatment, etc. can be performed, and in order to increase the surface energy, silicon treatment, fluorine treatment, olefin treatment, etc. can be performed.

In addition, a release agent or the like may be appropriately applied to the surface of the base material in advance in order to control the adhesiveness with a semi-cured layer described later. The semi-cured layer described later can be used by peeling the base material after bonding it to the polarizer. Further, in a state where a semi-cured layer described later is laminated on the base material, the optical properties and mechanical properties can be adjusted by appropriately stretching each base film.

<Liquid crystalline composition layer>

The liquid crystal composition layer is a layer made of a specific polymerizable liquid crystal composition.

(liquid crystalline compound)

The liquid crystal compound contained in the specific polymerizable liquid crystal composition is a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond.

As such a polymerizable group, specifically, a (meth)acryloyl group, a vinyl group, a styryl group, an allyl group, etc. are mentioned, for example, and a (meth)acryloyl group is preferable.

The liquid crystalline compound is preferably a rod-like liquid crystalline compound or a discotic liquid crystalline compound, and is more preferably a rod-like liquid crystalline compound because display performance improves when the obtained polarizing plate is used for an image display device.

Regarding the rod-like liquid crystalline compound, for example, those described in paragraphs [0045] to [0066] of Japanese Unexamined Patent Publication No. 2009-217256 are exemplified, and these contents are incorporated herein by reference.

Moreover, as a discotic liquid crystalline compound, for example, paragraph [0025] - [0153] of Unexamined-Japanese-Patent No. 2006-301614, paragraph [0020] - [0122] of Unexamined-Japanese-Patent No. 2007-108732, Japanese Unexamined Patent Publication 2010-244038, [0012] - what was described in [0108] paragraph is mentioned, These content is integrated in this specification.

The liquid crystalline compound is preferably fixed in a vertically aligned state from the viewpoint of adjusting the optical properties of the optically anisotropic layer described later.

For example, a layer in which a rod-shaped liquid crystalline compound is immobilized in a vertically aligned state can function as a positive C-plate. In addition, the layer in which the discotic liquid crystalline compound is immobilized in a vertically aligned state can function as a negative A-plate.

In the present invention, vertical alignment refers to an alignment state in which the normal direction of the layer and the long axis direction (director) of the liquid crystal molecules are parallel in the case of a rod-shaped liquid crystalline compound, and in the case of a disctic liquid crystalline compound, It refers to an alignment state in which the normal direction of the layer and the disk plane of the liquid crystal molecules are parallel. Further, the normal direction of the layer, the direction of the major axis of the liquid crystal molecules or the disk plane of the liquid crystal molecules may be within a range of ±5° from parallel, more preferably within ±3°, and still more preferably within ±2°. , more preferably within ±1°.

In the present invention, the specific polymerizable liquid crystal composition preferably exhibits a smectic phase for the reason that it can achieve both optical stability at a higher level in terms of adhesion to a polarizer and optical stability when applied to an image display device, and isotropic phase. It is more preferable to present the nematic phase and the smectic phase in this order on the low temperature side. In addition, it is preferable that the semi-cured layer mentioned later is a layer in which a specific polymerizable liquid crystal composition was immobilized in a smectic phase.

(photopolymerization initiator)

As the photopolymerization initiator contained in the specific polymerizable liquid crystal composition, for example, "Latest UV curing technology" {Kijutsu Joho Kyokai} (1991), p. 159, and “UV curing system” by Kiyomi Kato (1 year of Heisei, published by Sogo Kijutsu Center), p. Examples described in 65 to 148 can be given. In addition, α-carbonyl compounds (described in each specification of US Patent Publication Nos. 2367661 and 2367670), acyloinethers (described in US Patent Publication No. 2448828), α-hydrocarbon substituted aromatic acyloin compounds (USA Patent Publication No. 2722512), polynuclear quinone compound (described in each specification of US Patent Publication No. 3046127 and US Patent Publication No. 2951758), a combination of triarylimidazole dimer and p-aminophenyl ketone (described in US Patent Publication No. 3549367) , acridine and phenazine compounds (described in Japanese Laid-Open Patent Publication No. 60-105667, US Patent Publication No. 4239850) and oxadiazole compounds (described in US Patent Publication No. 4212970), acylphosphine oxide compounds (Japanese Publication No. 4239850) Patent Publication No. 63-040799, Japanese Patent Publication No. 5-029234, Japanese Unexamined Patent Publication No. Hei 10-095788, Japanese Unexamined Patent Publication No. Hei 10-029997), etc. are mentioned.

Examples of commercially available photo-cleavage type photo-radical polymerization initiators include "Irgacure 651", "Irgacure 184", "Irgacure 819" and "Irgacure 819" manufactured by BASF (former Chiba Specialty Chemicals Co., Ltd.). Irgacure 907", "Irgacure 1870", "Irgacure 500", "Irgacure 369", "Irgacure 1173", "Irgacure 2959", "Irgacure 4265", "Irgacure "Gacure 4263", "Irgacure 127", "Irgacure OXE01", "Irgacure OXE02", etc., "Kayacure DETX-S" and "Kayacure BP-100" manufactured by Nippon Kayaku Co., Ltd. , "Kayacure BDMK", "Kayacure CTX", "Kayacure BMS", "Kayacure 2-EAQ", "Kayacure ABQ", "Kayacure CPTX", "Kayacure EPD", "Kayacure ITX" , "Kayacure QTX", "Kayacure BTC", "Kayacure MCA", etc., "Esacure (KIP100F, KB1, EB3, BP, X33, KTO46, KT37, KIP150, TZT)" manufactured by Sartomer, etc. there is.

In the present invention, in the semi-curing step described later, since formation of a semi-curing layer satisfying the curing profile shown in formulas (1) and (2) described later becomes easy, as a photopolymerization initiator, hydroxyacetophenone-based photopolymerization It is preferable to use together an initiator and an oxime ester type photoinitiator.

As a hydroxyacetophenone type photoinitiator, specifically, for example, 1-hydroxy-cyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl -1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one , 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc. are mentioned.

Specific examples of the oxime ester photopolymerization initiator include 1.2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanone, and 1-[9]. -Ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), etc. are mentioned.

(copolymer)

In the semi-curing step described below, a specific polymerizable liquid crystal composition is repeated represented by the following formula (A) for the reason that formation of a semi-cured layer satisfying the curing profile shown in formulas (1) and (2) described later becomes easy. It is preferable to contain the copolymer which has unit A and repeating unit B represented by following formula (B).

The reason why the formation of the semi-cured layer becomes easy is not clear in detail, but the present inventors have a repeating unit A represented by the following formula (A) to the surface (air interface) opposite to the base material of the liquid crystal composition layer , It is estimated that the copolymer is unevenly distributed and it is because the base material of the liquid crystalline composition layer can control the polymerization rate of the surface on the opposite side by having the repeating unit B represented by the following formula (B).

[Formula 1]

In the formula (A), R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ¹ represents -O-, -(C=O)O-, -O(C=O)-, 2 Represents a divalent linking group composed of at least one selected from the group consisting of a valent aliphatic chain group and a divalent aliphatic cyclic group, and R ² is an alkyl group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, or -Si( R ^a21 )(R ^a22 ) Represents a group containing O-. R ^a21 and R ^a22 each independently represent an alkyl group having 1 to 12 carbon atoms which may have a substituent.

In the formula (B), R ³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ² represents -O-, -(C=O)O-, -O(C=O)-, 2 Represents a divalent linking group composed of at least one selected from the group consisting of a valent aliphatic chain group and a divalent aliphatic cyclic group, and R ⁴ represents a group represented by the following formula (B-1) or (B-2). * indicates a binding position with L ² .

[Formula 2]

R ¹ in the formula (A) and R ³ in the formula (B) each independently represent a hydrogen atom or an alkyl group of 1 to 20 carbon atoms, preferably a hydrogen atom or an alkyl group of 1 to 10 carbon atoms, and a hydrogen atom Alternatively, an alkyl group having 1 to 4 carbon atoms is more preferable, and a hydrogen atom or a methyl group is more preferable.

L ¹ in the formula (A) and L ² in the formula (B) are each independently -O-, -(C=O)O-, -O(C=O)-, a divalent aliphatic chain group; and a divalent linking group composed of at least one selected from the group consisting of divalent aliphatic cyclic groups. Further, -(C=O)O- indicates that a carbon atom on the R ¹ (or R ³ ) side is bonded to C=O, and R ² (or R ⁴ ) and O are bonded, and -O(C =O)- indicates that the carbon atom on the R ¹ (or R ³ ) side is bonded to O, and R ² (or R ⁴ ) and C=O are bonded.

As the divalent aliphatic chain group represented by L ¹ or L ² , an alkylene group having 1 to 20 carbon atoms is preferable, and an alkylene group having 1 to 10 carbon atoms is more preferable.

As the divalent aliphatic cyclic group represented by L ¹ or L ² , a C3-C20 cycloalkylene group is preferable, and a C3-C15 cycloalkylene group is more preferable.

As L ¹ or L ² , -(C=O)O- or -O(C=O)- is preferable, and -(C=O)O- is more preferable.

In the formula (A), the alkyl group (fluoroalkyl group) having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom represented by R ² is preferably a fluoroalkyl group having 1 to 18 carbon atoms, and has 2 to 18 carbon atoms. It is more preferable that it is a 15-fluoroalkyl group. Moreover, as for the number of fluorine atoms in a fluoroalkyl group, it is preferable that it is 1-25, it is more preferable that it is 3-21, and the thing of 5-21 is most preferable.

Moreover, as a group containing -Si(R ^a21 )(R ^a22 )O- represented by R ² in the formula (A), a repeating unit (polysiloxane structure) containing a siloxane bond is exemplified.

In this invention, it is preferable that the repeating unit A represented by the said formula (A) is a repeating unit represented by the following formula (A1) from a viewpoint of raw material availability.

[Formula 3]

In the formula (A1), R ¹⁰ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom or a fluorine atom. m and n each independently represent an integer of 1 to 20, and m+n represents an integer of 4 to 20.

As a monomer constituting such repeating unit A, specifically, for example, 2-(perfluorobutyl)ethyl(meth)acrylate, 2-(perfluorohexyl)ethyl(meth)acrylate, 1H, 1H,7H-dodecafluoroheptyl methacrylate, 4-(perfluoropentyloxy)benzyl acrylate, etc. are mentioned.

As said copolymer, the following copolymer is illustrated specifically, for example.

[Formula 4]

1000-500000 are preferable and, as for the weight average molecular weight (Mw) of the said copolymer, 2000-50000 are more preferable.

Here, the weight average molecular weight of the copolymer is defined as a value in terms of polystyrene by GPC (Gel Permeation Chromatograph) measurement. The weight average molecular weight of the high molecular compound is measured using, for example, EcoSEC HLC-8320GPC (manufactured by Tosoh Corporation) as a GPC apparatus, three TSKgel SuperAWM-H (manufactured by Tosoh Corporation) as a column, and NMP (N-methylphenol) as an eluent. Rolidone), and measured under the measurement conditions of a flow rate of 0.50 ml/min and a temperature of 40°C, and can be calculated as a polystyrene conversion value.

The content in case the specific polymerizable liquid crystal composition contains the copolymer is a specific polymerizable liquid crystal composition for the reason that the optical stability at the time of applying to a polarizer and the optical stability at the time of application to a higher level can be made compatible with a higher level. It is preferable that it is 0.1-5.0 mass parts with respect to the total solid content of.

(adhesion improver)

It is preferable that the specific polymerizable liquid crystal composition contains an adhesion improving agent represented by the following formula (I) because the adhesiveness to the polarizer becomes better.

Formula (I) (Z) _n -L ¹⁰⁰ -(Q) _m

Here, in formula (I), Z represents a substituent having a polymerizable group, n represents an integer of 0 to 4, and when n is an integer of 2 to 4, Z of 2 or more may be the same or different. do.

Q represents a substituent containing at least one boron atom, m represents 1 or 2, and when m is 2, the two Qs may be the same or different.

In addition, L ¹⁰⁰ represents an n+m valent linking group. However, when n represents 0 and m represents 1, L ¹⁰⁰ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkynyl group, represents an unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.

In the formula (I), as a substituent having a polymerizable group represented by Z, for example, (meth)acrylate group, styryl group, vinyl ketone group, butadiene group, vinyl ether group, oxiranyl group, aziridinyl group and substituents including an oxetane group and the like.

Among these, a substituent containing a (meth)acrylate group, a styryl group, an oxiranyl group or an oxetane group is preferable, and a substituent containing a (meth)acrylate group or a styryl group is more preferable.

In particular, as the substituent containing a (meth)acrylate group, a group having an ethylenically unsaturated double bond represented by the following general formula (V) is preferable.

[Formula 5]

In the general formula (V), R ³ is a hydrogen atom or a methyl group, preferably a hydrogen atom.

In the above general formula (V), L ¹ is a single bond, -O-, -CO-, -NH-, -CO-NH-, -COO-, -O-COO-, an alkylene group, or an aryl group. It is a divalent linking group selected from the group consisting of a rene group, a heterocyclic group, and a combination thereof, preferably a single bond, -CO-NH- or -COO-, and particularly preferably a single bond or -CO-NH-.

In the formula (I), n represents an integer of 0 to 4, preferably represents 0 or 1, more preferably represents 1.

Moreover, m represents 1 or 2, and it is preferable to represent 1.

In addition, as L ¹⁰⁰ , for example, as a divalent linking group, a single bond, -O-, -CO-, -NH-, -CO-NH-, -COO-, -O-COO-, an alkylene group, or an aryl divalent linking groups selected from rene groups, heteroaryl groups, and combinations thereof.

Among these, a substituted or unsubstituted arylene group is more preferable.

In addition, the alkyl group, alkenyl group, alkynyl group, aryl group, and heteroaryl group represented by L ¹⁰⁰ are synonymous with R ¹ and R ² in the following general formula (VI), and the preferred ranges are also the same.

Moreover, as a substituent which these groups have, the substituent etc. which were described in the paragraph [0046] of Unexamined-Japanese-Patent No. 2013-054201 are mentioned, for example.

In the above formula (I), Q is a substituent containing at least one boron atom, and is preferably a group capable of being adsorbed and bonded to a polymer film.

For example, when a polymer film has a hydroxyl group or a carboxyl group on the surface by surface treatment or the like, a group capable of bonding to the hydroxyl group or carboxyl group of the polymer film is preferable.

In addition, the "group capable of being adsorbed and bound to the polymer film" means a group capable of chemical adsorption to the polymer film by interacting with the structure of the material constituting the polymer film.

Examples of the substituent containing at least one boron atom include substituents represented by the following general formula (VI).

[Formula 6]

In the general formula (VI), R ¹ and R ² each independently represent a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group.

In addition, R ¹ and R ² in the above general formula (VI) may constitute a linking group composed of an alkylene group, an aryl group, or a combination thereof by connecting R ¹ and R ² .

In the general formula (VI), the substituted or unsubstituted aliphatic hydrocarbon group represented by each of R ¹ and R ² includes a substituted or unsubstituted alkyl group, an alkenyl group, and an alkynyl group.

Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a hexadecyl group and an octadecyl group. , Eicosyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-methylhexyl group, cyclopentyl group, Linear, branched or cyclic alkyl groups, such as a cyclohexyl group, 1-adamantyl group, and 2-norbornyl group, are mentioned.

Specific examples of the alkenyl group include straight-chain, branched, or A cyclic alkenyl group is mentioned.

Specific examples of the alkynyl group include ethynyl group, 1-propynyl group, 1-butynyl group, and 1-octynyl group.

Specific examples of the aryl group include those in which one to four benzene rings formed a condensed ring, and those in which a benzene ring and an unsaturated 5-membered ring formed a condensed ring. Specific examples include a phenyl group, a naphthyl group, anthryl group, and a phenanthryl group , indenyl group, acena butenyl group, fluorenyl group, pyrenyl group and the like.

Examples of the substituted or unsubstituted heteroaryl group represented by each of R ¹ and R ² in the general formula (VI) include at least one hetero atom selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom. Examples include those made into a heteroaryl group by removing one hydrogen atom on the heteroaromatic ring.

Specific examples of the heteroaromatic ring containing at least one heteroatom selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom include pyrrole, furan, thiophene, pyrazole, imidazole, triazole, oxazole, isoxazole, and oxaazole. Diazole, thiazole, thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene, dibenzothiophene, indazolebenzimidazole, anthranil, benzisoxazole, benzoxazole, Benzothiazole, purine, pyridine, pyridazine, pyrimidine, pyrazine, triazine, quinoline, acridine, isoquinoline, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, pteridine, etc. can be heard

As R ¹ and R ² in the general formula (VI), they are preferably hydrogen atoms.

Further, R ¹ and R ² in the formula (VI) and L ¹⁰⁰ in the formula (I) may be further substituted with one or more substituents if possible. One or more of these hydrocarbon groups may be substituted by an arbitrary substituent. Examples of the substituent include monovalent non-metal atom groups excluding hydrogen.

As molecular weight of the compound represented by said Formula (I), 120-1200 are preferable and 180-800 are more preferable.

Specific examples of the compound represented by the formula (I) include the following compounds in addition to the compounds exemplified in the specific examples described in paragraphs [0035] to [0040] of Unexamined-Japanese-Patent No. 2007-219193, the contents of which are described herein. incorporated into the specification. Of course, the present invention is not limited to these specific examples.

[Formula 7]

[Formula 8]

[Formula 9]

When the specific polymerizable liquid crystal composition contains the adhesion improving agent represented by the formula (I), the content is 0.5% to 7% based on the mass of the liquid crystalline compound (total mass when two or more liquid crystalline compounds are used together). It is preferable that it is mass %, it is more preferable that it is 1-5 mass %, and it is more preferable that it is 3-5 mass %.

(other additives)

You may mix|blend other additives with a specific polymeric liquid crystal composition within the range which does not deviate from the meaning of this invention.

As another additive, a vertical alignment agent is mentioned, for example. As the vertical alignment agent, it is preferable to use a pyridinium compound or an onium compound, and by containing these compounds, while acting as a vertical alignment agent that promotes vertical alignment in the polymer film interface of the liquid crystal compound, liquid crystal It also contributes to improving the adhesion of the interface between the liquid crystal layer and the polymer film in which the alignment state of the compound is fixed. Regarding pyridinium compounds, for example, Japanese Unexamined Patent Publication No. 2007-093864, [0030] to [0052], for onium compounds, for example, Japanese Unexamined Patent Publication No. 2012-208397, [0027] to [0058] There is, and these contents are incorporated in this specification.

In addition, the liquid crystal layer in which the alignment state of the liquid crystalline compound is fixed, an air interface side alignment control agent (for example, a copolymer containing a repeating unit having a fluoroaliphatic group) that controls the alignment on the air interface side is added as necessary. may contain.

Moreover, the liquid crystal composition may contain a non-liquid crystal polymerizable monomer. As the polymerizable monomer, a compound having a vinyl group, a vinyloxy group, an acryloyl group or a methacryloyl group is preferable. Specifically, a polyfunctional monomer having two or more polymerizable reactive functional groups, for example, a polyhydric alcohol and (meth)acrylic acid ester [for example, ethylene glycol di(meth)acrylate, butanedioldi(meth) Acrylate, hexanediol di(meth)acrylate, 1,4-cyclohexane diacrylate, pentaerythritol tetra(meth)acrylate], pentaerythritol tri(meth)acrylate, trimethylolpro Feintry(meth)acrylate, trimethylolethane tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexane(meth) acrylate, pentaerythritol hexa(meth)acrylate, 1,2,3-cyclohexane tetramethacrylate, polyurethane polyacrylate, polyester polyacrylate], the above ethylene oxide modified products, vinyl Benzene and its derivatives (e.g. 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinylsulfone (e.g. divinylsulfone) , acrylamide (eg methylenebisacrylamide) and methacrylamide. You may use together 2 or more types of the said monomer.

(solvent)

A specific polymerizable liquid crystal composition may contain a solvent.

As the solvent, it can be appropriately selected from the viewpoints of being easy to form a uniform surface during coating and drying, being able to ensure liquid retention, having an appropriate saturated vapor pressure, and the like.

Specifically as such a solvent, for example, dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5- Trioxane, tetrahydrofuran, anisole, phenetole, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentane one, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, methyl 2-methoxyacetate, 2- Methyl ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2-methoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, di Acetone alcohol, methyl acetoacetate, ethyl acetoacetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, cyclohexyl alcohol, isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentane On, 2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate (PGMEA ), ethyl carbitol, butyl carbitol, hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, toluene, xylene, etc. You may use, and you may use 2 or more types together.

Among these, it is preferable to use at least one of methyl acetate, ethyl acetate, methyl ethyl ketone, acetone, methyl alcohol and ethyl alcohol.

When using such a solvent, it is preferable to use the solvent so that the concentration of the solid content of the specific polymerizable liquid crystal composition is in the range of 5 to 80% by mass, and it is preferable to use the solvent so that the concentration of the solid content is in the range of 10 to 75% by mass. More preferably, it is more preferable to use a solvent so that the concentration of the solid content is in the range of 15 to 70% by mass.

<Method of Forming Liquid Crystal Composition Layer>

The method of forming a liquid crystal composition layer composed of a specific polymerizable liquid crystal composition is not particularly limited, and examples include a method of coating a specific polymerizable liquid crystal composition on the above-described substrate, a method of forming a solution film of a specific polymerizable liquid crystal composition, and the like. can be mentioned, and among them, the method of coating is preferable.

As a coating method, a dip coat method, an air knife coat method, a curtain coat method, a roller coat method, a wire bar coat method, a gravure coat method, a slide coat method, and an extrusion coat method (die coat method) (Japanese Patent Laid-Open Publication 2003-164788), a known method such as a micro gravure coating method is used, and among them, a micro gravure coating method and a die coating method are preferable.

In the present invention, two or more liquid crystal composition layers may be laminated. In addition, when two or more layers are laminated, the semi-cured layer on the side to be bonded to the polarizer needs to satisfy Expressions (1) and (2) described later.

In addition, when two or more layers of the liquid crystal composition are laminated, surface treatment such as provision of an easily bonding layer between the layers, corona treatment, or plasma treatment may be performed as necessary.

[Semi-curing process]

The semi-curing step of the method for producing a polarizing plate of the present invention is a step of curing the liquid crystal composition layer formed in the layer formation step to form a semi-curing layer that satisfies the following formulas (1) and (2).

In addition, Sa and Sb in following formula (1), and P1, P2, and P3 in following formula (2) are as the above-mentioned.

1.5≤Sa/Sb≤5.0 Equation (1)

0.03≤(P1-P2)/P3≤0.2 Equation (2)

In the present invention, the semi-curing step is performed by the following formulas (1-1) and (2-2) for the reason that the optical stability when applied to a polarizer and the optical stability when applied to an image display device can be made compatible at a higher level. It is preferable that it is a process of forming a semi-cured layer that satisfies.

1.6≤Sa/Sb≤4.0 Equation (1-1)

0.05≤(P1-P2)/P3≤0.1 Equation (2-1)

In the semi-curing step, it is effective to cure the liquid crystalline composition layer by combining irradiation with ultraviolet rays and heat treatment before, simultaneously with, or after irradiation.

The heat treatment performed in combination with irradiation with ultraviolet rays is not particularly limited as long as the semi-cured layer is not inhibited, but is preferably 40 to 150°C, more preferably 40 to 110°C.

The time required for heat treatment varies depending on the molecular weight of the component used, interaction with other components, viscosity, etc., but is preferably 15 seconds to 1 hour, more preferably 20 seconds to 30 minutes, and 30 seconds More preferably -5 minutes.

The method of irradiation with ultraviolet rays is not particularly limited, and curing is preferably performed by irradiation with ultraviolet rays in an irradiation amount of 10 mJ/cm ² to 1000 mJ/cm ² using an ultraviolet lamp.

In particular, it is preferable that it is 100-1000 mJ/cm< ² > as a cumulative irradiation amount for the reason that adhesiveness with a polarizer and optical stability at the time of application to an image display apparatus can be made compatible at a higher level.

In the present invention, since formation of a semi-cured layer satisfying the curing profile shown in the above formulas (1) and (2) becomes easy, it is preferable to irradiate ultraviolet rays in an atmosphere with an oxygen concentration of 2000 ppm or more.

[Bonding process]

The bonding step of the manufacturing method of the polarizing plate of the present invention is to bond the polarizer and the semi-cured layer formed in the semi-curing step using an ultraviolet curing adhesive, and the polarizer, the ultraviolet curing adhesive, the semi-curing layer, and the base material are laminated in this order It is a process of manufacturing a laminated body.

<Polarizer>

The polarizer is not particularly limited as long as it is a member having a function of converting light into specific linearly polarized light, and conventionally known absorption-type polarizers and reflection-type polarizers can be used.

As the absorption type polarizer, an iodine-based polarizer, a dye-based polarizer using a dichroic dye, a polyene-based polarizer, and the like are used. An iodine-based polarizer and a dye-based polarizer include a coating type polarizer and a stretching type polarizer, and both can be applied, but a polarizer produced by adsorbing iodine or a dichroic dye to polyvinyl alcohol and stretching is preferable.

In addition, as a method of obtaining a polarizer by stretching and dyeing in the state of a laminated film in which a polyvinyl alcohol layer is formed on a substrate, Japanese Patent Publication No. 5048120, Japanese Patent Publication No. 5143918, Japanese Patent Publication No. 4691205, Japanese Patent Publication No. 4751481 and Japanese Patent Publication No. 4751486 can be cited, and well-known techniques relating to these polarizers can also be preferably used.

As the reflective polarizer, a polarizer in which thin films of different birefringence are laminated, a wire grid polarizer, a polarizer in which a cholesteric liquid crystal having a selective reflection region and a quarter wave plate are combined, and the like are used.

Among them, from the viewpoint of more excellent adhesion, polyvinyl alcohol-based resin (-CH ₂ -CHOH- as a repeating unit polymer. In particular, at least one selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymer ) It is preferable that it is a polarizer containing.

In the present invention, the thickness of the polarizer is not particularly limited, but is preferably 1 μm to 50 μm, more preferably 2 μm to 30 μm, and still more preferably 3 μm to 20 μm.

<UV curable adhesive>

As the UV curing adhesive, if it is classified according to its curing mode, radical polymerization type adhesive containing a radical polymerizable compound, cationic polymerization type adhesive containing a cationic polymerizable compound, etc. may be mentioned, and depending on the chemical species of the adhesive component, If classified, an acrylic resin adhesive, an epoxy resin adhesive, etc. are mentioned.

As said radically polymerizable compound, the radically polymerizable compound which has an unsaturated double bond, such as a (meth)acryloyl group and a vinyl group, for example is mentioned, Specifically, a multifunctional radically polymerizable compound, two or more in a molecule Polyfunctional radically polymerizable compounds having a polymerizable group, (meth)acrylates having a hydroxyl group, acrylamide, acryloylmorpholine, and the like are exemplified. These compounds may be used individually by 1 type, and may use 2 or more types together.

As said cationically polymerizable compound, the compound which has an epoxy group or an oxetanyl group is mentioned, for example. The epoxy compound is not particularly limited as long as it has at least two epoxy groups in the molecule, and compounds described in detail in Japanese Patent Laid-Open No. 2004-245925 can be used, for example.

Moreover, you may use combining a radically polymerizable compound and a cationically polymerizable compound.

As such an ultraviolet curable adhesive, a known one can be used, for example, Japanese Unexamined Patent Publication No. 2017-134413, Japanese Unexamined Patent Publication No. 2015-040283, Japanese Unexamined Patent Publication No. 2015-187744, Japanese Unexamined Patent Publication 2015- An ultraviolet curable adhesive described in No. 011094 or the like can be used.

The thickness of the ultraviolet curable adhesive at the time of bonding of the polarizer and the semi-cured layer is not particularly limited, and is preferably about 0.01 to 30 μm, more preferably 0.01 to 10 μm, and still more preferably 0.05 to 5 μm.

In the present invention, in bonding the polarizer and the semi-cured layer with an ultraviolet curable adhesive, the surface to be bonded to the polarizer of the semi-cured layer for the purpose of improving the adhesive strength or improving the wettability of the adhesive to the surface of the semi-cured layer Treatment (for example, glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, etc.) may be performed, or an easily bonding layer may be formed. For example, the material, formation method, etc. of the easily bonding layer described in Unexamined-Japanese-Patent No. 2007-127893, Unexamined-Japanese-Patent No. 2007-127893 etc. can be used.

[Main curing process]

The main curing step of the method for producing a polarizing plate of the present invention is a step of curing the laminate produced in the bonding step to produce a polarizing plate having a polarizer and an optically anisotropic layer in which a semi-cured layer is further cured.

In the main curing step, it is effective to cure the laminate produced in the bonding step by combining irradiation with ultraviolet rays and heat treatment before irradiation, simultaneously with or after irradiation.

The heat treatment performed in combination with irradiation with ultraviolet rays is not particularly limited as long as the semi-cured layer is not inhibited, but is preferably 40 to 150°C, more preferably 40 to 110°C.

The time required for heat treatment varies depending on the molecular weight of the component used, interaction with other components, viscosity, etc., but is preferably 15 seconds to 1 hour, more preferably 20 seconds to 30 minutes, and 30 seconds More preferably -5 minutes.

The method of irradiation with ultraviolet rays is not particularly limited, and curing is preferably performed by irradiation with ultraviolet rays in an irradiation amount of 10 mJ/cm ² to 1000 mJ/cm ² using an ultraviolet lamp.

In particular, it is preferable that it is 100-1000 mJ/cm< ² > as a cumulative irradiation amount for the reason that adhesiveness with a polarizer and optical stability at the time of application to an image display apparatus can be made compatible at a higher level.

[Peel process]

The manufacturing method of the polarizing plate of this invention may have the peeling process of peeling a base material from the polarizing plate produced by the said main hardening process after the said main hardening process from a viewpoint of achieving thickness reduction of the polarizing plate produced.

As a method of peeling the base material, any appropriate method can be employed. For example, a method of transferring a substrate to a peeling tape may be employed.

[Manufacturing method of optical film (first aspect)]

The manufacturing method (1st aspect) of the optical film of this invention is a manufacturing method of the optical film which has a base material and a semi-cured layer.

The manufacturing method (first aspect) of the optical film of the present invention is a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator on a substrate and a layer forming step of forming a liquid crystalline composition layer, and a semi-curing step of curing the liquid crystalline composition layer to form a semi-cured layer satisfying the above formulas (1) and (2).

Here, the layer formation step in the manufacturing method (first aspect) of the optical film of the present invention is the specific polymerizable liquid crystal composition described above among the layer forming steps described in the manufacturing method of the polarizing plate of the present invention, hydroxy It is an aspect using an acetophenone-based photopolymerization initiator and an oxime ester-based photopolymerization initiator as essential components.

Moreover, the semi-hardening process in the manufacturing method (1st aspect) of the optical film of this invention is the same process as the semi-hardening process demonstrated in the manufacturing method of the polarizing plate of this invention.

That is, the manufacturing method (1st aspect) of the optical film of this invention is one of the suitable aspects of the layer formation process and semi-curing process in the manufacturing method of the polarizing plate of this invention.

[Optical Film Manufacturing Method (Second Mode)]

The manufacturing method (2nd aspect) of the optical film of this invention is a manufacturing method of the optical film which has a base material and a semi-cured layer.

The manufacturing method (2nd aspect) of the optical film of this invention is a liquid crystal compound which has a polymerizable group, a photoinitiator, the repeating unit A represented by the above-mentioned formula (A), and the above-mentioned formula (B) on a base material A layer formation step of forming a liquid crystal composition layer comprising a polymerizable liquid crystal composition containing a copolymer having a repeating unit B represented by , and curing the liquid crystal composition layer to satisfy the above-described formulas (1) and (2) It has a semi-curing step of forming a semi-curing layer.

Here, the layer formation step in the optical film manufacturing method (second aspect) of the present invention is the specific polymerizable liquid crystal composition described above among the layer formation steps described in the polarizing plate manufacturing method of the present invention. It is an aspect using the copolymer which has the repeating unit A represented by Formula (A) and the repeating unit B represented by the above-mentioned formula (B) as an essential component.

In addition, the semi-curing process in the manufacturing method (2nd aspect) of the optical film of this invention is the same process as the semi-curing process demonstrated in the manufacturing method of the polarizing plate of this invention.

That is, the manufacturing method (2nd aspect) of the optical film of this invention is one of the suitable aspects of the layer formation process and semi-curing process in the manufacturing method of the polarizing plate of this invention.

In the manufacturing method of the optical film of the present invention, also in any of the above-described first and second aspects, it is preferable that the above-described specific polymerizable liquid crystal composition exhibits a smectic phase, and a nematic phase and a smectic phase are formed on the low-temperature side of the isotropic phase. It is more preferable to show tick phases in this order. And it is preferable that the semi-cured layer formed by the semi-curing process is a layer in which the above-described specific polymerizable liquid crystal composition was fixed in a smectic phase.

[Polymerizable liquid crystal composition (first aspect)]

The polymerizable liquid crystal composition (first aspect) of the present invention is a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator.

Here, the polymerizable liquid crystal composition (first aspect) of the present invention is a specific polymerizable liquid crystal composition described in the layer formation step of the method for producing a polarizing plate of the present invention, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization It is an aspect using an initiator as an essential component.

That is, the polymerizable liquid crystal composition (first aspect) of the present invention is one of suitable aspects of the specific polymerizable liquid crystal composition used in the layer formation step in the method for producing a polarizing plate of the present invention.

[Polymerizable liquid crystal composition (second aspect)]

The polymerizable liquid crystal composition (second aspect) of the present invention comprises a liquid crystal compound having a polymerizable group, a photopolymerization initiator, repeating unit A represented by the above formula (A), and repeating unit B represented by the above formula (B) A polymerizable liquid crystal composition containing a copolymer having

Here, the polymerizable liquid crystal composition (second aspect) of the present invention is a repeating unit A represented by the formula (A) and the above It is an aspect using the copolymer which has repeating unit B represented by one Formula (B) as an essential component.

That is, the polymerizable liquid crystal composition (second aspect) of the present invention is one of suitable aspects of the specific polymerizable liquid crystal composition used in the layer formation step in the method for producing a polarizing plate of the present invention.

Example

The present invention will be described in more detail below based on examples. The materials, usage amount, ratio, treatment content, treatment procedure, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the examples shown below.

[Example 1]

[Layer Formation Step]

As a substrate, a cyclic olefin polymer film (Aton film, Re = 125 nm, Rth = 63 nm, film thickness 25 μm, manufactured by JSR Corporation) was used.

One side of the substrate was subjected to corona treatment at a discharge rate of 125 W·min/m ² , and a polymerizable liquid crystal composition prepared with the following composition was applied to the corona treated side with a #3.0 wire bar to form a liquid crystal composition layer. formed

-------------------------------------------------- --------------

Polymeric liquid crystal composition

-------------------------------------------------- --------------

100.0 parts by mass of the following liquid crystalline compound L-1

· Hydroxyacetophenone-based photopolymerization initiator

(Irgacure 127, manufactured by BASF) 5.0 parts by mass

·Oxime ester-based photopolymerization initiator

(OXE-01, manufactured by BASF) 2.0 parts by mass

・Monomer (ATMMT, manufactured by Shin Nakamura Chemical Industry Co., Ltd.) 8.0 parts by mass

・4.5 parts by mass of the following orientation aid A-1

・ 2.0 parts by mass of the following orientation aid A-2

・0.3 parts by mass of leveling agent B-1 below

・Acetone 438.5 parts by mass

・PGMEA 48.7 parts by mass

-------------------------------------------------- --------------

・Liquid crystalline compound L-1

A mixture of the following liquid crystalline compounds (RA) (RB) (RC) in a ratio of 83:15:2 (mass ratio)

[Formula 10]

・Orientation aid A-1

[Formula 11]

・Orientation aid A-2

[Formula 12]

・Leveling agent B-1 (weight average molecular weight: 15000, numerical value in the following formula: mass%)

[Formula 13]

[Semi-curing process]

After the layer formation process, the mixture was heated for 90 seconds with warm air at 70° C. for drying of the solvent of the composition and alignment aging of the liquid crystalline compound.

Subsequently, ultraviolet irradiation (500 mJ/cm ² ) was performed at 40° C. in an air atmosphere to fix the alignment of the liquid crystalline compound, thereby forming a semi-cured layer. Rth of the semi-cured layer was -100 nm. In addition, the hardening profile shown by the said formula (1) and (2) in the formed semi-hardened layer is as showing in Table 1 below.

[Bonding process]

<Preparation of UV curable adhesive>

An ultraviolet curable adhesive having the following composition was prepared.

-------------------------------------------------- ----------------

UV curable adhesive

-------------------------------------------------- ----------------

・Aronix M-220 (manufactured by Toagosei Co., Ltd.) 20 parts by mass

60 parts by mass of 4-hydroxybutyl acrylate (manufactured by Nihon Kasei Co., Ltd.)

- 20 parts by mass of acrylic acid -2-ethylhexyl (manufactured by Mitsubishi Chemical Corporation)

・Irgacure 907 (manufactured by BASF) 1.5 parts by mass

・KAYACURE DETX-S (manufactured by Nippon Kayaku Co., Ltd.) 0.5 parts by mass

-------------------------------------------------- ----------------

<Combination>

On the surface of the semi-cured layer opposite to the base material (cyclic olefin polymer), the prepared ultraviolet curable adhesive was applied to a thickness of 0.5 μm.

After that, the adhesive-coated surface was bonded to the polarizer, and a laminate was produced in which the polarizer, the ultraviolet curing adhesive, the semi-cured layer, and the substrate were laminated in this order.

[Main curing process]

After the bonding step, 1000 mJ/cm ² of ultraviolet rays was irradiated from the substrate side of the optical film at 40°C in an air atmosphere. Then, it dried at 60 degreeC for 3 minutes, and produced the polarizing plate of Example 1.

[Examples 2 to 7 and Comparative Examples 1 to 5]

A polarizing plate was produced by the same method as in Example 1 except that the composition of the polymerizable liquid crystal composition was changed to the composition shown in Tables 1 to 3 below and the conditions of the semi-curing step were changed to the conditions shown in Tables 1 to 3 below. did.

In addition, in following Table 2 and Table 3, structures, such as polymerization inhibitor C-1, are as showing below.

Polymerization inhibitor C-1 (Mw: 20000)

[Formula 14]

Polymerization inhibitor C-2 (Mw: 20000)

[Formula 15]

Liquid crystalline compound L-2

[Formula 16]

Liquid crystalline compound L-3

[Formula 17]

Monomer L-4

[Formula 18]

[Example 8]

[Production of polarizing plate]

The photo-alignment film-forming material described in Example 1 of International Publication No. 2016/002722 was prepared and applied onto an 80 μm TAC film with a bar coater.

After application, it was dried on a hot plate at 120°C for 1 minute to remove the solvent, and a photoisomerization composition layer having a thickness of 0.3 µm was formed.

A photo-alignment film was formed by irradiating the obtained photoisomerization composition layer with polarized ultraviolet rays (10 mJ/cm ² , using an ultra-high pressure mercury lamp).

On the photo-alignment layer, the following composition of the first liquid crystal layer was applied with a bar coater to form a composition layer. The formed composition layer was once heated to 110° C. on a hot plate and then cooled to 60° C. to stabilize orientation. Thereafter, while maintaining at 60°C, the alignment was fixed by ultraviolet irradiation (500 mJ/cm ² , using an ultra-high pressure mercury lamp) in a nitrogen atmosphere (oxygen concentration: 100 ppm) to prepare a first optically anisotropic layer having a thickness of 2 μm.

-------------------------------------------------- --------------

Composition of the first liquid crystal layer

-------------------------------------------------- --------------

Cyclopentanone 16.2 parts by mass

・MEK 51.1 parts by mass

・Liquid crystalline compound L-2 13.2 parts by mass

・Liquid crystalline compound L-3 13.2 parts by mass

・Liquid crystalline compound L-4 5.0 parts by mass

・Polyethylene glycol #200 diacrylate 0.5 parts by mass

·Oxime ester-based photopolymerization initiator

(OXE-01, manufactured by BASF) 0.5 parts by mass

・0.2 parts by mass of the leveling agent P-1 described below

-------------------------------------------------- --------------

・Leveling agent P-1 (in the following formula, mass ratio a:b:c = 50:30:20)

[Formula 19]

The surface of the first optically anisotropic layer was subjected to corona treatment with a discharge amount of 125 W·min/m ² .

Thereafter, using the polymerizable liquid crystal composition used in Example 7, a layer forming step, a semi-curing step and a bonding step were performed in the same manner as in Example 7, and a polarizer, an ultraviolet curing adhesive, a semi-curing layer, and a first optical anisotropy A laminate having the layers and the TAC film in this order was produced.

Next, in the same manner as in Example 7, after performing the main curing process, the TAC film was peeled to produce a polarizing plate.

[evaluation]

[Adhesiveness]

Evaluation was performed by the cross-cutting method described in JIS-K-5600-5-6-1.

Specifically, 100 crosscuts were placed at 1 mm intervals on the surface of the base material (the first optically anisotropic layer in Example 8) of the prepared polarizing plate, and an adhesion test was performed with cellophane tape (manufactured by Nichiban Co., Ltd.). After attaching a new cellophane tape, it peeled off and judged according to the following criteria. A result is shown to following Tables 1-3.

A: Separation of cells during crosscut does not occur

B: 50% or more and less than 100% of cells without peeling during crosscut

C: 20% or more and less than 50% of cells without peeling during crosscut

D: Less than 20% of cells without peeling during crosscut

It is the standard of A, B, and C that there is no problem in practical use. It is preferable that it is the standard of A.

[Optical Stability]

<Production of liquid crystal display device>

The polarizing plate was peeled from the liquid crystal cell of iPad (registered trademark, manufactured by Apple Inc.) and used as a liquid crystal cell in IPS mode.

Instead of the peeled polarizing plate, the polarizing plate produced above was bonded together to the liquid crystal cell using SK2057 by Soken Chemical Co., Ltd., and the liquid crystal display device was produced.

The produced liquid crystal display device was exposed in an environment of 65°C and 90% for 500 hours, and display performance was observed.

Specifically, for each liquid crystal display device produced, using a measuring instrument "EZ-Contrast XL88" (manufactured by ELDIM), 1° intervals from 0° in azimuth (horizontal direction) to 359° in the counterclockwise direction, and 0 polar angle The luminance (Yw) in white display and the luminance (Yb) in black display are measured at 1° intervals from ° (front direction) to 88°, and the contrast ratio (Yw/Yb) is calculated, and the azimuth angle is 45 The contrast ratio was evaluated in the direction of ° and polar angle 60 ° according to the following evaluation criteria. A result is shown to following Tables 1-3.

A: The area where the contrast ratio is high is particularly wide and particularly excellent (contrast ratio: 200 or more)

B: The area with high contrast ratio is wide and excellent (contrast ratio: 150 or more and less than 200)

C: Narrow area with high contrast ratio (contrast ratio: 100 or more and less than 150)

D: Narrow area with high contrast ratio (contrast ratio: less than 100)

[Table 1]

[Table 2]

[Table 3]

From the results shown in Tables 1 to 3, when a cured layer that does not satisfy the curing profile shown in the above-mentioned formulas (1) and (2) is formed, the adhesion between the polarizer and the optically anisotropic layer is poor, or the polarizer and the optical Even if the adhesiveness of the anisotropic layer was good, it turned out that the optical stability at the time of application to an image display device was inferior (Comparative Examples 1-5).

On the other hand, when a semi-cured layer satisfying the curing profile shown in the above-described formulas (1) and (2) is formed, the adhesion between the polarizer and the optically anisotropic layer becomes good, and the prepared polarizing plate is applied to an image display device. , it was found that the optical stability became good (Examples 1 to 8).

Claims (7)

A layer formation step of forming a liquid crystal composition layer comprising a polymerizable liquid crystal composition containing a photopolymerization initiator and a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond, on a substrate;
A semi-curing step of curing the liquid crystalline composition layer to form a semi-curing layer satisfying the following formulas (1) and (2);
A bonding step of bonding the polarizer and the semi-cured layer using an ultraviolet curable adhesive to produce a laminate in which the polarizer, the ultraviolet curable adhesive, the semi-cured layer, and the base material are laminated in this order;
The manufacturing method of the polarizing plate which has a main hardening process of hardening the said laminated body and producing the polarizing plate which has the said polarizer and the optically anisotropic layer formed by further hardening of the said semi-cured layer.
1.5≤Sa/Sb≤5.0 Equation (1)
0.03≤(P1-P2)/P3≤0.2 Equation (2)
In the above formula (1), Sa is from the surface of the semi-cured layer on the opposite side of the substrate to the distance of 1/4 of the film thickness of the semi-cured layer after Br staining of the ethylenically unsaturated double bonds contained in the semi-cured layer In the region of , the integrated value of the secondary ion intensity derived from the Br ion detected by the time-of-flight secondary ion mass spectrometry is shown.
In the above formula (1), Sb is the area from the surface of the semi-cured layer on the substrate side after Br staining of the ethylenically unsaturated double bonds contained in the semi-cured layer to a distance of 3/4 of the film thickness of the semi-cured layer represents the integral value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in .
In the above formula (2), P1 represents the absorbance at the maximum absorption peak in the range of wave numbers 820 to 800 cm ^-1 in the infrared absorption spectrum, and P2 represents the absorbance at the minimum wave number in the range of 840 to 800 cm ^-1 . It represents the absorbance, and P3 represents the absorbance at the maximum absorption peak in the range of 1800 to 1650 cm ⁻¹ wave number. In claim 1.
The manufacturing method of the polarizing plate which has a peeling process of peeling the said base material from the said laminated body after the said main hardening process. A method for producing an optical film having a base material and a semi-cured layer,
A layer formation step of forming a liquid crystal composition layer comprising a liquid crystal composition layer comprising a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator on a substrate,
A method for producing an optical film comprising a semi-curing step of curing the liquid crystalline composition layer to form a semi-curing layer satisfying the following formulas (1) and (2).
1.5≤Sa/Sb≤5.0 Equation (1)
0.03≤(P1-P2)/P3≤0.2 Equation (2)
In the above formula (1), Sa is from the surface of the semi-cured layer on the opposite side of the substrate to the distance of 1/4 of the film thickness of the semi-cured layer after Br staining of the ethylenically unsaturated double bonds contained in the semi-cured layer In the region of , the integrated value of the secondary ion intensity derived from the Br ion detected by the time-of-flight secondary ion mass spectrometry is shown.
In the above formula (1), Sb is the area from the surface of the semi-cured layer on the substrate side after Br staining of the ethylenically unsaturated double bonds contained in the semi-cured layer to a distance of 3/4 of the film thickness of the semi-cured layer represents the integral value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in .
In the above formula (2), P1 represents the absorbance at the maximum absorption peak in the range of wave numbers 820 to 800 cm ^-1 in the infrared absorption spectrum, and P2 represents the absorbance at the minimum wave number in the range of 840 to 800 cm ^-1 . It represents the absorbance, and P3 represents the absorbance at the maximum absorption peak in the range of 1800 to 1650 cm ⁻¹ wave number. A method for producing an optical film having a base material and a semi-cured layer,
A polymerizable liquid crystal composition containing, on a substrate, a copolymer having a liquid crystal compound having a polymerizable group, a photopolymerization initiator, and a repeating unit A represented by the following formula (A) and a repeating unit B represented by the following formula (B) A layer forming step of forming a liquid crystalline composition layer formed;
A method for producing an optical film comprising a semi-curing step of curing the liquid crystalline composition layer to form a semi-curing layer satisfying the following formulas (1) and (2).
1.5≤Sa/Sb≤5.0 Equation (1)
0.03≤(P1-P2)/P3≤0.2 Equation (2)
In the above formula (1), Sa is from the surface of the semi-cured layer on the opposite side of the substrate to the distance of 1/4 of the film thickness of the semi-cured layer after Br staining of the ethylenically unsaturated double bonds contained in the semi-cured layer In the region of , the integrated value of the secondary ion intensity derived from the Br ion detected by the time-of-flight secondary ion mass spectrometry is shown.
In the above formula (1), Sb is the area from the surface of the semi-cured layer on the substrate side after Br staining of the ethylenically unsaturated double bonds contained in the semi-cured layer to a distance of 3/4 of the film thickness of the semi-cured layer represents the integral value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in .
In the above formula (2), P1 represents the absorbance at the maximum absorption peak in the range of wave numbers 820 to 800 cm ^-1 in the infrared absorption spectrum, and P2 represents the absorbance at the minimum wave number in the range of 840 to 800 cm ^-1 . It represents the absorbance, and P3 represents the absorbance at the maximum absorption peak in the range of 1800 to 1650 cm ⁻¹ wave number.

In the formula (A), R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ¹ represents -O-, -(C=O)O-, -O(C=O)-, 2 Represents a divalent linking group composed of at least one selected from the group consisting of a valent aliphatic chain group and a divalent aliphatic cyclic group, and R ² is an alkyl group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, or -Si( R ^a21 )(R ^a22 ) Represents a group containing O-. R ^a21 and R ^a22 each independently represent an alkyl group having 1 to 12 carbon atoms which may have a substituent.
In the formula (B), R ³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ² represents -O-, -(C=O)O-, -O(C=O)-, 2 Represents a divalent linking group composed of at least one selected from the group consisting of a valent aliphatic chain group and a divalent aliphatic cyclic group, and R ⁴ represents a group represented by the following formula (B-1) or (B-2). * indicates a binding position with L ² .

According to claim 3 or claim 4,
The method for producing an optical film, wherein the polymerizable liquid crystal composition exhibits a nematic phase and a smectic phase in this order on the low temperature side of the isotropic phase, and the semi-cured layer is a layer in which the polymerizable liquid crystal composition is fixed in a smectic phase. A polymerizable liquid crystal composition containing a copolymer having a liquid crystalline compound having a polymerizable group, a photopolymerization initiator, and a repeating unit A represented by the following formula (A) and a repeating unit B represented by the following formula (B).

In the formula (A), R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ¹ represents -O-, -(C=O)O-, -O(C=O)-, 2 Represents a divalent linking group composed of at least one selected from the group consisting of a valent aliphatic chain group and a divalent aliphatic cyclic group, and R ² is an alkyl group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, or -Si( R ^a21 )(R ^a22 ) Represents a group containing O-. R ^a21 and R ^a22 each independently represent an alkyl group having 1 to 12 carbon atoms which may have a substituent.
In the formula (B), R ³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ² represents -O-, -(C=O)O-, -O(C=O)-, 2 Represents a divalent linking group composed of at least one selected from the group consisting of a valent aliphatic chain group and a divalent aliphatic cyclic group, and R ⁴ represents a group represented by the following formula (B-1) or (B-2). * indicates a binding position with L ² .

delete